A whole-cortex probabilistic diffusion tractography connectome

Abstract

<jats:title>Abstract</jats:title><jats:p>The WU-Minn Human Connectome Project (HCP) is a publicly-available dataset containing state-of-art structural, functional, and diffusion-MRI for over a thousand healthy subjects. While the planned scope of the HCP included an anatomical connectome, resting-state functional-MRI forms the bulk of the HCP’s current connectomic output. We address this by presenting a full-cortex connectome derived from probabilistic diffusion tractography and organized into the HCP-MMP1.0 atlas. Probabilistic methods and large sample sizes are preferable for whole-connectome mapping as they increase sensitivity to low-probability connections. We find that overall connectivity is lognormally distributed and decays exponentially with tract length, that connectivity reasonably matches macaque histological tracing in homologous areas, that contralateral homologs and left-lateralized language areas are hyperconnected, and that hierarchical similarity influences connectivity. This work helps fulfill the promise of the HCP and will make possible comparisons between the underlying structural connectome and functional connectomes of various modalities, brain states, and clinical conditions.</jats:p>

Brain simulation augments machine-learning-based classification of dementia

“…Moreover, we observed that features related to important AD-related functional networks (as the default-mode network (Grothe, Teipel et al 2016) and the visual ventral stream (Grill-Spector and Malach 2004, Kravitz, Saleem et al 2013)) are involved with a higher feature importance rank. A table with the full name and corresponding functional network according to Rosen and Halgren (Rosen and Halgren 2020) for the 50 highest ranked features is given in Table 2 .…”

“…Parcellation adapted from(Glasser, Coalson et al 2016). Functional networks adapted from(Rosen and Halgren 2020). DS: Dorsal Stream, VS: Ventral Stream, SMA: Supplementary motor area…”

The α-Synuclein Origin and Connectome Model (SOC Model) of Parkinson’s Disease: Explaining Motor Asymmetry, Non-Motor Phenotypes, and Cognitive Decline

“…It follows that only approximately 1% of cerebral neurons project to the contralateral hemisphere. This assertion is supported by modern data from the human connectome project showing that cerebral connectivity is completely dominated by ipsilateral connections [30], and that less than 1-2% of hippocampal projections, for example, are contralateral [31]. The fraction of crossing connections from brainstem nuclei in humans has not been reported in detail.…”

“…The scarce contralateral projections underlie an-other element of the SOC model. Most cortical re-gions and some subcortical structures send most of their commissural projections to their contralateral homologs, so called homotypic connections (illustrated in Fig.3 A) [ 30 ]. If brain-first PD is most com-monly initiated in a single unilateral structure, such as the entorhinal cortex or amygdala, the first structures to be affected in the contralateral hemisphere will also be the amygdala or entorhinal cortex [ 33, 45 ].…”

Dynamical differential covariance recovers directional network structure in multiscale neural systems

“…In order to compare the functional connectivity metrics to the underlying corticocortical white matter connectivity, we reorganized our previously published diffusion-MRI based structural connectome [15] in which connectivity was assessed among the 360 cortical areas of the HCP-MMP1.0 atlas [7]. Of the 100 IC nodes, 46 are composed of at least 40% cortical voxels (Fig.S6A) and as the dMRI connectome was restricted to corticocortical relationships, we limited the scope of our analyses to these nodes.…”